It is quite extraordinary, philosophically speaking, that according to the orthodox interpretation: (a) quantum mechanics is a complete and comprehensive theory of microphysics, and yet (b) the role of measurement, in quantum mechanics, cannot be analyzed in terms of the collective effects of the microphysical particles making up the apparatus. It follows that, if the orthodox interpretation is correct, the measurement apparatus and its quantum physical effects cannot be accounted for microreductively. This is significant because it is widely believed that the relation between physical wholes and parts is microreductive. Indeed, many philosophers are persuaded of the inevitability of universal microreduction to the basic elements of microphysics. This is the viewpoint embodied in the program for the unity of science, espoused in recent years, most notably by Robert Causey (1977).
It is quite extraordinary, philosophically speaking, that according to the orthodox interpretation: (a) quantum mechanics is a complete and comprehensive theory of microphysics, and yet (b) the role of measurement, in quantum mechanics, cannot be analyzed in terms of the collective effects of the microphysical particles making up the apparatus. It follows that, if the orthodox interpretation is correct, the measurement apparatus and its quantum physical effects cannot be accounted for microreductively. This is significant because it is widely believed that the relation between physical wholes and parts is microreductive. Indeed, many philosophers are persuaded of the inevitability of universal microreduction to the basic elements of microphysics. This is the viewpoint embodied in the program for the unity of science, espoused in recent years, most notably by Robert Causey (1977).
The difficulties of the old quantum theory were largely dispelled by the development of quantum mechanics in the 1920s. First Heisenberg (1925) developed the rather abstract matrix mechanics and soon after Schro¨dinger (1926; see also Eckart, 1926) developed the physically more appealing wave mechanics. Subsequently he showed them to be mathematically equivalent. The physicists were greatly relieved; now they had once again a mathematical formalism that enabled the results of experiments to be calculated. It was possible to move forward. It is certainly a very elegant and indeed beautiful formalism, and does enable the results of many physical measurements to be calculated with great accuracy. It is used daily by atomic and nuclear physicists; there is no other way to make calculations. From the earliest days there has been intense debate about the interpretation of quantum mechanics, and it shows no signs of being settled; if anything it is becoming more intense over the years. As Penrose has remarked, no one understands quantum mechanics. Feynman (1967; see also Sykes, 1994) also admitted that ‘nobody understands quantum mechanics’, and Einstein once remarked: ‘I have thought a hundred times as much about the quantum problems as I have about general relativity theory’ (Pais, 1994, p. 57). It should therefore be evident that the most that can be done here is to try to show where the real difficulties lie, and how the failure to recognize that quantum mechanics is an essentially statistical theory has led to a series of confusing quantum paradoxes. It is just these paradoxes that have often been used to support theological speculations. It is useful to ask what ‘understanding quantum mechanics’ actually means. Certainly it means being able to calculate the results of many measurements. The same applies to Newton’s theory of gravitation, which we understand in the sense that we can use it as a basis of calculation, although we do not really understand the gravitational force itself. Very often, especially in modern physics, the mathematical formalism does not give us the sort of intuitive physical feeling for what is going on that we often obtain from classical mechanics. Perhaps we can never achieve more than this for quantum mechanics. In classical mechanics we can assume that a property that is measured objectively exists prior to the interaction of the measuring apparatus with the observed system. Quantum mechanics, however, ‘is incompatible with the proposition that measurement discovers some unknown but pre-existing property’ (Peres, 1997, p. 14). There is an important distinction between mysteries and absurdities. We may be forced to live with mysteries, but there is no reason why we should put up with absurdities such as the wave-particle duality, tunnelling through potential barriers, acausal events and the collapse of the wave function. These are the quantum paradoxes that will be discussed later on. They arise within the Copenhagen interpretation of quantum mechanics and are solved by other interpretations. These alternative interpretations enable us to make conjectures about what is going on, even though we cannot understand it in detail. This is acceptable and a stimulus to further research. It is certainly difficult enough to understand quantum mechanics, but there is no need to try to visualize logical absurdities in the effort to do so. Quantum mechanics is a mathematical formalism that makes it possible to calculate the results of some experiments. Anything more than this, such as questions about the interpretation of what is measured and whether it tells us what is actually going on in the system being studied, belongs to philosophy. Thus we are concerned here with what is essentially a philosophical debate; if it were just a matter of physics the debate would have been settled long ago. One of the difficulties is that it invokes the results of experiments and uses the language of quantum mechanics. Inevitably this language uses philosophical terms and then it is easy to give the impression that the philosophical propositions are in some way entailed by the physical results. These in turn can influence theological thinking. In order to be quite clear which arguments are justified and which are not, it is essential to separate the three levels of discourse: physical, philosophical and theological. Our task is to relate these together, and this immediately raises the traditional problems of the philosophy of science, including the relation of experiment to theory, and of theory to explanation. We begin by discussing experiments, distinguishing between those that are real and those that are imaginary.
Quantum mechanics is our most successful physical theory. It underlies our very detailed understanding of atomic physics, chemistry, and nuclear physics, and the many technologies to which physical systems in these regimes give rise. Additionally, relativistic quantum mechanics is the basis for the standard model of elementary particles, which very successfully gives a partial unification of the forces operating at the atomic, nuclear, and subnuclear levels. However, from its inception the probabilistic nature of quantum mechanics, and the fact that “quantum measurements” in the orthodox formulation appear to require the intervention of non-quantum mechanical “classical systems,” have led to speculations by many physicists, mathematicians, and philosophers of science that quantum mechanics may be incomplete. Among the Founding Fathers of quantum theory, Einstein and Schrödinger were both of the opinion that quantum mechanics is in some way unsatisfactory, and this view has been amplified in more recent profound work of John Bell, among others. In an opposing camp, many others in the physics, mathematics, and philosophy communities have attempted to provide an interpretational foundation in which quantum mechanics remains a complete and self-contained system. Among the Founding Fathers, Bohr, Born, and Heisenberg maintained that quantum mechanics is a complete system, and a number of recent proposals have been made to improve upon or to provide alternatives to their “Copenhagen Interpretation.” The debate continues, and has spawned an enormous literature.
The newly revised edition of this well-known book categorizes prevalent views on measurement as described by quantum mechanics, discusses basics agreed to by many who on other issues disagree, and describes some of the problems. Although many paragraphs rest unchanged from the first (1991) edition, results found since 1991 are used to reorganize and sharpen the focus of the book, so that even the old paragraphs are now understood differently and more clearly. One advance in the second edition is a new and more general no-go theorem; another is separation of formal derivations from interpretation. The dozen or so definitions essential to following the book even casually are stated clearly. By this means the authors succeed pretty well in achieving their stated desire to make the book comprehensible to those who do not share their philosophic predispositions. While I differ in philosophy from the authors, attending to their discussion uncovered weaknesses in my own thinking and improved it. The mathematical language of quantum mechanics expresses a system under measurement by states (as rays in a Hilbert space) and a hamiltonian operator, distinct from the apparatus that produces outcomes, which is expressed by a positive operator-valued (POV) measure. In this way quantum language separates state preparation from state measurement. Often the Hilbert space is viewed as a tensor product of subspaces, allowing further conceptual separations. The authors take the stance that quantum mechanics calls for splitting the empirical world into parts, the most essential being (1) objective systems S (to be observed) and (2) apparatus A (preparation and registration devices that produces outcomes (or, as the authors write, definite pointer values) of the observed system). In some interpretations, one or both of an observer and an environment appear as additional parts. What is to be included in the system S versus the apparatus A is not specified by the language, but is open to the theoretician; a probe, for example, can be analysed as either part of the apparatus or as part of the system, as was discussed by von Neumann in work cited by the authors. With what should a theory of measurement be concerned? A broad division of approaches is defined by how one answers the question: should one try to do away with the cut between measuring apparatus and system? The authors phrase this as a choice of REFERENT, a term which in my mind puts them on shaky semantic ground; anyway The Quantum Theory of Measurement is concerned with implications of the `yes'. The book unfolds with the power of a tragedy, in which the logical consequences lead, step-by-step, to the statement and proof of theorem 6.2.1, which, roughly speaking, asserts the non-existence of a solution to the problem of getting definite pointer values from measuring apparatus that exhibits the superposition demanded by its description as a quantum system. Possible responses to this theorem are discussed, among them the many-worlds interpretation and a modification of quantum mechanics that elevates decoherence to a principle. Citations of the literature are thorough, and many points of view are crisply summarized. The book is indispensable to both those who work in the broad direction chosen by the authors and to those who wish to set any other direction in context.
Although it is 70 years old, there are still areas of quantum theory which are open to interpretation. This book deals with such interpretational problems, and in particular with the issue of the measurement process. The main theme is whether quantum mechanics can be viewed as a (semantically) complete theory, namely as a theory capable of describing not only the physical object under observation but also the measuring instruments used to detect the properties of that physical object. The problematic aspects arise from the fact that the measuring instruments themselves behave as classical physical systems. Thus, we are faced with the open problem of the transition from the quantum to the classical, or more explicitly, the problem of why the composition of many quantum micro-objects gives rise to classical macro-objects. This book goes carefully, exhaustively, and deeply into the interpretational problems of quantum mechanics induced by the measurement process. The solution of many relevant issues, as well as the problems that remain unsolved, emerge clearly. The discussion itself is self-contained and the technical parts are reader-friendly. This book is of value to graduate students and researchers who have an interest in the physical, mathematical, and philosophical foundations of quantum mechanics.
The Orthodox interpretation of quantum mechanics, which followed the Copenhagen Interpretation but was enhanced by primarily Werner Heisenberg and John von Neumann into a fully developed theory, brought in, among others, the role of measurement, available choices and response of the quantum system.It is, more consistent and clear than other interpretations of quantum mechanics as it provides account of the interactions of observers with the external world.As such, the Orthodox interpretation does a lot more than just account for physical interactions in the atomic world, which was the original goal of quantum mechanics in the early part of the twentieth century.In this article we present several issues that may have been answered or need further development, such as measurement and observation, what is Nature and who the observer is.Extending Orthodox quantum mechanics, leading to universal non-dual Awareness may provide a consistent and integrated view of reality and is consistent with advances in mathematical theory.An issue of paramount importance is what are the philosophical underpinnings or ontological view of the quantum nature of the universe and the role of human minds, observations and choices.
Unseen is an essential component of the Muslim faith as mentioned in many verses in Qur’an and many Hadiths. Thus, the significance of having faith is to believe in something unseen. Accordingly, a belief in nothingness is simply a rejection of the belief in the unseen. It should be recalled here that Allah (S.W.T), Who has the full knowledge of the worlds of the seen and the unseen, has guaranteed the true believers great rewards. Allah (S.W.T) says: Indeed, those who fear their Lord Unseen will have forgiveness and great reward (Al-Mulk, 12). Scientists believe that the accurate image of the real ingredient can never be entirely understood in this physical Universe since humans are limited by their physical apparatuses. Hence, there must be other states, but humans have no apparatus to observe and understand them. What exactly does the unseen mean? Quantum physics, which had its bases at the beginning of the 20th century, is an extremely dedicated pattern of science, which unlike Newtonian physics investigates and clarifies how the whole thing in the visible world comes into being. It is fundamentally studying the nature of physical existence beginning at the subatomic, unseen, level. Additionally, quantum physics divides nature into two parts; on one side of the partition there is the observed system whereas there is the observer on the other side. One difficulty is where you place the isolating line, which relies upon who is doing the observation? More topical findings in quantum physics are rapidly mutating the world in an exceedingly extraordinary and optimistic manner. Unlike classical physics, awareness crosses the threshold of quantum theory and circumstance at the onset. Thus, there is no way to interpret quantum theory without in some way addressing awareness. Unambiguously, awareness takes an obvious and strong role. Otherwise stated, it is avoided by presenting the concept of hidden variables. They, generally, start with the assumption that the physical world should be dealt with unaccompanied by the human observer. The Many Worlds interpretation, consistently, is vital to quantum interpretations since it brings about the ultimate observer outside of space and time. This has obvious theistic implications; therefore, the theologians have not been very keen to attribute to Allah (S.W.T) the role of ultimate observer who brings the whole quantum Universe into being. Arguably, there are parallel Universes mentioned within the Qur’an that one does not have access to. These worlds are widely talked about within the Qur’an, the world of the unseen and seen, Allah (S.W.T) says in surah Al-Ra’d:9; “All-Knower of the unseen and the seen, the Greatest, the Highest”. Accordingly, believe in the Ghaib: literally means a thing not Seen. This investigation, with the aim of redirecting the focus of the scientists, emphasized that there are no discrepancies between some of Quantum physics’ interpretation and the belief in the unseen. Therefore, the systematic analysis posed by the authors in this study, through three Qur’anic examples, namely, Moses and Al- Khidr, Joseph (P.U.H) and regaining sight for Jacob (P.U.H) and Prophet Solomon’s death and the Jinns, attempt to analyze these apparently manifold subjects, with the purpose of analyzing the Qur’anic concepts and universalizing the perceptions of quantum physics.